The present invention relates to a geographic information system (GIS) used in navigation systems and traffic control systems, more particularly, the present invention relates to a geographic information system which searches within a short time a record containing objects such as roads and buildings stored in a map database. This system can access to an object and a traffic regulation only available under a specific condition, and take this specific information therein.
Several prior arts have been proposed about the GIS, e.g. the Japanese Patent Application Non-examined Publication No. H09-245056 discloses an idea about storing data in a map database. The data shows occurrence and extinction of an object. The occurrence of an object indicates that the object is newly built, and the extinction of the object indicates that the object is removed. When attributes associated with the object, such as the data of occurrence and extinction of object, and the names and locations of the object, are updated, the date of the occurrence and extinction are recorded in the map database together with the map including the object. When a geographic information system searches some data, if a date is specified, the system can extract only the objects available on the date specified. Then the objects extracted can be displayed on a map or on a list.
The Japanese Patent Application Non-examined Publication No. H08-227497 discloses an idea of forming a route by selecting roads. This idea is to store temporary traffic regulations available only at a certain time, on a specified date, or during a limited period in a map database. Then the system searches roads available on a specific time and date for selecting a route on that particular date.
The conventional GIS disclosed in the Japanese Patent Application Non-examined Publication No. H09-245056 must ascertain every data about occurrence and extinction of objects stored in the map database for extracting an object available at a specified time and date. Thus this process takes a lot of time.
Another conventional GIS disclosed in the Japanese Patent Application Non-examined Publication No. H08-227497 cannot control the data such as a skiing ground, a beach house available only in a season, an emergency traffic regulation due to the weather such as snowfall or heavy rains or a temporary traffic control due to an accident, pupils"" going to elementary school. Those seasonal objects and temporary regulations are not indicated on a calendar, so that the system cannot store those data therein.
The present invention addresses the problems discussed above and aims to provide a GIS that can extracts objects available on a certain date within a short time.
Another object of the present invention is to provide a GIS which can control temporary traffic regulations or events such as seasonally available, or due to the climates, accidents or temporary agreements within a local area, although the times and dates of those temporary traffic regulations and the events are not expressed in a calendar.
The present invention thus concerns a GIS as defined in the appended claims.